<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
	<button class="btn">添加一条新的访客信息</button>
	<table border="">
		<tr class="tr">
			<th>序列号</th>
			<th>姓名</th>
			<th>年龄</th>
			<th>操作</th>
		</tr>
	</table>
	
    <script>
       var info = [{
                   name: "胡杭",
                   age: 16
               }, {
                   name: "胜明",
                   age: 22
               }, {
                   name: "军毅",
                   age: 21
               }, {
                   name: "晓华",
                   age: 13
               }, {
                   name: "盛聪",
                   age: 23
               }, {
                   name: "侦剑",
                   age: 32
               }, {
                   name: "红翔",
                   age: 25
               }, {
                   name: "超维",
                   age: 18
               }, {
                   name: "士琪",
                   age: 22
               }, {
                   name: "艳华",
                   age: 20
               }];
		var btn = document.getElementsByClassName("btn")
		console.log(btn)
		var table = document.querySelector(".table")
		console.log(table)
		btn.onclick = function(){
			var tr = document.createElement("tr");
			n = 0;
			ty.innerHTML = "<th>"+(n+1)+"</th>"+
							"<th>"+info(n).name+"</th>"+
							"<th>"+info(1).are+"</th>"+
							"<button>"+删除+"</button>"
			n++
			table.append(tr);
		};
    </script>
</body>

</html>